In recent years, an organic EL display (hereinafter, referred to as an “organic EL display”) using an organic electroluminescence device (hereinafter, referred to as an “organic EL device”) has received attention. An organic EL device that is used in an organic EL display includes an anode, a cathode and a light emitting layer placed between the anode and the cathode, wherein light is emitted as a hole and an electron injected from the anode and the cathode, respectively, are combined in the light emitting layer.
An organic EL device has the advantage that a production process is simple, and an organic layer such as a light emitting layer or the like can be formed by a coating method with which the area of a device is easily increased. Specifically, an organic layer can be formed using a solution including an organic compound contained in the organic layer, and an organic solvent. As for a method for forming an organic layer of an organic EL device, there have been proposed a method for producing an organic EL device, wherein concentration of moisture in an atmosphere for forming a light emitting layer is 1000 ppm or less (Patent Document 1), and a method for producing an organic EL device, wherein an organic layer is prepared by a wet process in an inert gas atmosphere having a moisture content of 10 ppm or less and an oxygen concentration of 10 ppm or less (Patent Document 2).